In the commercial growing of flowers and produce, the seeds from which plants are grown can be divided into two basic classes. One class is "easy to plant seeds", such as corn and peas, and the other class is "hard to plant seeds", such as lettuce and celery. The easy to plant seeds are those seeds which are sufficiently large and of sufficient uniform configuration that they can be easily and effectively dispensed, one at a time, by various mechanical dispensing mechanisms or devices suitable for field use and which are economical and practical to make, use and maintain. The hard to plant seeds are those seeds which are so small and of such shape that they do not lend themselves to being dispensed in a uniform, one at a time manner by those mechanical seed dispensing means provided by the prior art.
To enable seed dispensing means provided by the prior art to effectively dispense small, hard to plant seeds, it is common practice to imbed or encase the seeds in clay pellets of a size and shape particularly suitable for being worked upon by the seed dispensing means of the prior art. In the case of pelletized seeds, such as noted above, the pellets in which the seeds are imbedded are the structures which are worked upon by the dispensing means, not the seeds, per se.
While the pelletizing of hard to plant seeds has enabled commercial growers to effect the planting of such seeds by means of existing and available seed dispensing means, the required use of pelletized seeds presents several serious shortcomings. First, the cost of pelletized seeds is excessive; second, the rate of failure of pelletized seeds to germinate is considerably greater than that of raw or unpelletized seeds; third, to effect germination of pelletized seeds, excessive water must be used to dissolve or break down the pellets; and fourth, the source of supply of pelletized seeds is restricted to those seed companies with the facilities to pelletize seeds.
One pound of raw lettuce seed contains about 450,000 seeds and presently sells for about $ 28.00 per pound. One pound of pelletized lettuce seeds contains about 45,000 seeds and presently sells for about $ 7.00 per pound. Accordingly, the cost of pelletized seeds is two to three times greater than the cost of raw seeds.
In use, subsequent to planting pelletized seeds, the planted fields must be subjected to heavy and protracted overhead watering to effect adequate wetting and breaking down of the pellets and resulting germination of the seeds; while in the case of raw seeds, moderate irrigation of the fields and moistening of the soil in which the seeds are planted is required to effect germination. As a rule, the cost of the additional amount of water required to reduce the pellets and effect germination of pelletized seeds is many times the cost of the seeds and constitutes a direct additional cost in the use of such seed.
Further, the soil conditions of some farm land is such that the heavy watering required in the use of pelletized seed would result in such adverse effect that the use of such seed is rendered impossible or impractical.
In the case of pelletized seeds, the process to which the seeds are subjected when being pelletized results in a high loss of germination. This loss of germination is compounded by a high secondary loss of germination which results from the failure of some pellets to effectively break down in the soil, after planting and watering.
Due to the high loss of germination experienced in the use of pelletized seeds, it is often necessary that a grower use considerably more pellets or seeds per acre than should be required, thus further increasing the cost of planting.
It is to be understood that the term "clay" in describing pelletized seeds is used in a generic sense and is intended to include materials other than clay which are or might be used to coat and carry seeds.
As a result of the above noted shortcomings and/or disadvantages to be found in the use of pelletized seeds, there has been a long recognized want and need for a simple, practical mechanical seed dispensing device suitable for infield use and capable of effectively dispensing small, irregularly shaped, hard to plant seeds, one at a time and at a substantially uniform or steady rate.
It is an object and feature of my invention, therefore, to provide a novel automatic seed planter which is capable and effective to dispense small, irregularly shaped seeds, one at a time, at a substantially uniform rate.
Another object and feature of my invention is to provide a seed dispensing device of the character referring to above which is extremely simple and economical to make, and which can be effectively carried by a vehicle or other mobile field equipment to dispense seeds in a field prepared for the planting and over which the vehicle or equipment is operated.
A further object and feature of the present invention is to provide a seed dispensing means or device of the general character referred to above which includes few parts, each of which parts is easy and simple to manufacture, use and assemble and a device which is highly effective and dependable in operation.
I have discovered that the above objects and advantages are achieved by a device which includes seed supply means, an elongate substantially V-shaped, upwardly-opening seed receiving hopper related to and receiving seed from the supply means and having a lower seed outlet opening at one end, an elongate seed guide arranged within the hopper and cooperatively related with the outlet opening, and shaker means to vibrate the hopper and guide to cause seeds in the hopper to migrate downwardly and to move out through the outlet opening, one at a time, and at a substantially uniform rate.